Drug-resistant tuberculosis diagnosis since Xpert® MTB/RIF introduction in Papua New Guinea, 2012-2017.

SETTING: Xpert® MTB/RIF was introduced in Papua New Guinea in 2012 for the diagnosis of tuberculosis (TB) and of rifampicin-resistant TB (RR-TB), a marker of multi-drug-resistant TB (MDR-TB). OBJECTIVE: To assess the concordance of Xpert with phenotypic drug susceptibility testing (DST) performed at the supranational reference laboratory and to describe the patterns of drug-resistant TB observed. DESIGN: This was a retrospective descriptive study of laboratory data collected from April 2012 to December 2017. RESULTS: In 69 months, 1408 specimens with Xpert results were sent for mycobacterial culture and DST; Mycobacterium tuberculosis was cultured from 63% (884/1408) and DST was completed in 99.4%. The concordance between Xpert and culture for M. tuberculosis detection was 98.6%. Of 760 RR-TB cases, 98.7% were detected using Xpert; 98.5% of 620 MDR-TB cases were identified using phenotypic DST. Phenotypic resistance to second-line drugs was detected in 59.4% (522/879) of specimens tested, including 29 with fluoroquinolone resistance; the majority were from the National Capital District and Daru Island. CONCLUSION: The high concordance between phenotypic DST and Xpert in identifying RR-TB cases supports the scale-up of initial Xpert testing in settings with high rates of drug resistance. However, rapid DST in addition to the detection of RR-TB is required.

Impact of GxAlert on the management of rifampicin-resistant tuberculosis patients, Port Moresby, Papua New Guinea.

SETTING: GxAlert is an automatic electronic notification service that provides immediate Xpert® MTB/RIF testing results. It was implemented for the notification of patients with rifampicin resistant-tuberculosis (RR-TB) at Port Moresby General Hospital, Port Moresby, Papua New Guinea, in May 2015. OBJECTIVE: To determine if there were differences in pre-treatment attrition, the time to treatment initiation and patient outcomes in the 12 months pre- and post-introduction of GxAlert for RR-TB patients. DESIGN: This was a retrospective cohort study. RESULTS: The median time from Xpert testing to treatment initiation decreased from 35 days [IQR 13-131] prior to GxAlert to 10 days [IQR 3-29] after GxAlert (P = 0.001), with the cumulative proportion of patients initiating treatment within 30 days increasing from 25% (95%CI 17-37) to 54% (95%CI 44-64; P < 0.001) over these periods. However, our analysis of the time to treatment prior to the introduction of GxAlert suggests that a decrease had already occurred prior to implementation. There was no difference in interim clinical outcomes between the periods. CONCLUSION: Although a decrease in time to treatment initiation cannot be attributed to GxAlert, there was a significant improvement over the 2-year period, suggesting that considerable improvements have been made in timely RR-TB patient management in Port Moresby.